Gas exhaustion from locomotives and other furnaces



Apfil 1937. K. BA'SCQHANT 2,077,029

GAS EXHAUSTION FROM LOCOMOTIVES AND OTHER FURNACES Filed Dec. 12, 1951 Patented Apr. 13, 1937 PATE NT OFFICE GAS EXHAUSTION FROM LOGOMOTIVES AND OTHER FURNACES Karl Baschant, Berlin-charlottenburg, G81! many, assignor to Mineraloohemie A. G. fiir metallurgische und chemische Produkte,

Vienna, Austria Application December 12, 1931, Serial No. 580,676 In Germany March 14, 1930 1 1 Claims; '(01. 230-96) My invention refers to furnaces, more especially the furnaces of locomotives and other steam boilers, and has for one of its objects to provide tmeans'whereby the exhaustion of the gases of combustion from. the smoke box is rendered more efiicient than was hitherto possible.

The present invention relates more particu larly. to a blast pipe apparatus for use in loco- ;motives or other boilenfurnaces which is designed to utilize to a higher extent, than has hitherto been-done,l the large amount of heat stored in the smoke gases issuing from the smoke tubes of the boiler.

In accordance with this invention the smoke chimney gases and the-steam about to enter the or funnel communicating with the outer air. are forced to intermingle as intimately as possible in order to utilize the greatest possible part ofthe heat stored in the smoke gases for an increase of the potential energy ofthe mixture, thereby rendering it possibleto greatlyenlarge the blast pipe section and tothereby reduce the back pressure on the steam piston, so that the output as a wholeisgreatly increased and a substantial savr 1 ing of fuel obtained. l H To this .end the mixture ,of steam and smoke gas about to enterthe chimney is'throttled or.

crowded together and thereafter expanded and accelerated once or several times in one or a plurality of acceleration nozzles of the de Laval type, whose cross section decreases right above their lower inflow end to thereafter increase gradually up to the outflow end. In these nozzles, which are arranged above the blast pipe in. such manner that this pipe extends up to a point slightly below the plane of the narrowest crosssectional area of the nozzle, thesmokegas carried along by the draught is mixed with the steam in one or'more stages and in each stagetthe mix ture thus formed is reheated, momentarily thro'ttled and slowl'y expanded, whereby its ve locity is increased to the highest possible value.

Theblast pipe is preferably subdivided, in'a manner well known per se, into a great number of divisional tubes, all of which extend below and partlyalso into the acceleration nozzle disposed immediately above the blast pipe.

Afurther increase of the kinetic energy of the mixture of smoke gases and steam may be obtained by spraying preheated water into the path of the smoke gases before they enter the chimney, whereby superheated steam is developed at this point. 7

In the drawing afiixed to this specification and forming part thereof, several forms of apparatus l embodying my inventionare illustrated diagrammatically by way of example.

In the drawing,

Fig. 1 is a vertical axial section of the lower portion of the smokebox of a locomotive boiler according to one embodiment of my invention and Fig. 2 is a vertical transverse section of the same portion of the smoke-box, taken through the smoke stack on the line II-II in Fig. 1. I

Fig; 3 is a cross-section of a smoke boxwith another or intermediate nozzle inserted between the exhaust nozzle and the chimney. I

Fig. 4 is a cross-section of the exhaust nozzle on the line IV--IV in Figs. 1-3.

Figs. 5 and 6 are two further modifications of exhaust and acceleration nozzles according to this invention.

Fig. 7 illustrates the combination of an ordinaryblast pipe of large cross-sectional area with aparticularly powerful acceleration nozzle of the deLaval type, and

Figs. 8 and 9 are axialsections of chimneys provided with inserts to modify their inner cross-sectional area.

Referring to the drawing and first to Figs. 1 and 2, l is the smoke box of a locomotive, 2 is the outer shell, 3 is the end wall, 4 is the tube wall and 5 are some of the boiler tubes. 6 is the chimney, 7 is. the extension of the chimney and I4 is the blast pipe arranged below and in axial alignment with this extension and with the chimney proper. 9 is a guide plate leading upwardly in oblique direction from the bottom of the tube plate to and embracing the bottom part of the extension I of the chimney. ID are curved plates covering the corners formed between theshell 2 and the end wall 3 of the smoke box.

The chimney proper is formed with upwardly decreasing diameter, while the extension 1 is formed after the manner of a de- Laval nozzle. I6 is an acceleration nozzle of the de Laval type mounted on the blast pipe M in such a manner that the branch nozzles rise to different levels in the narrowbottom part of the deLaval nozzle. The total cross-sectional area of passage of the branch nozzles is greater than that of the normal blast pipe hitherto provided in an engine of the usual type.

The steam rising in the blast pipe creates in cooperation with the chimney a draught which causes the gases of combustion to pass through and. issue from the smoke tubes 5. On entering the smoke box I these gases are guided by the ascending plate 9. around the extension I of the chimney and are thus forced to change their direction of flow and to drop the particles of coal and cinders admixed with them before collecting around the head of the exhaust nozzle 16. The steam issuing from the branch nozzles [5 will intimately mix with the gases of combustion entering the acceleration or exhaust nozzle 16 of de Laval type from below and between the branch nozzles I5, the mixture being first crowded together and thereafter expanded.

owing to the particular cross-sectional form of exhaust nozzle l6. On issuing from the blast pipe the mixture of steam and gases carries along a further quantity of gases in the gap between the nozzles I6 and chimney I and this large volume of steam and gases is once more crowded together in the narrow bottom part of the chimney and thereafter allowed to expand in the top part thereof, the steam flowing through the exhaust nozzle [6 is increased and the mixture of steam and gases being first crowded together and thereafter allowed to expand, receives an acceleration and thereby is enable to carry away larger quantities of combustion gases per' unit of time.

This increase of velocity is obtained without any increase of the back pressure acting on the piston,the total cross-sectional area of passage of the branch nozzles l5 being considerably larger than that of the normal blast pipe nozzle in a locomotive of the same type.

The curved plates I covering the corners formed between the shell 2 and end wall 3 of the smoke box, which latter has the form of a spherical segment, prevent the formation of whirls and eddies in these corners and provide for a smooth flow of the gases of combustion in the smoke box and into contact with the steam cone.

In the modification illustrated in Fig. 3, the blast pipe I4 is again formed with a greater number of branch nozzles l5 (Fig. 4) of different length, which end on diiferent levels within an intermediate nozzle I 6 formed after the manner of a de Laval nozzle. Another intermediate nozzle I! of the de Laval type is inserted'between the extension I of the chimney and the exhaust nozzle.

In the modification illustrated in Fig. 5 the exhaust nozzle l8, which is formed with branch nozzles I9, is surmounted by an acceleration nozzle 20 ending in branch nozzles 2| of different length. Between these nozzles and the extension I of the chimney is mounted another acceleration nozzle 22 of the de Laval type.

Obviously in this device the steam entering the nozzle I8 is subdivided into a number of jets in the branch nozzles I9 and will intimately mix with the hot gases of combustion entering the nozzle 20 from below, a heat exchange being effected between the gases and the steam. The hot mixture on passing through the branchnozzles 2| will again be subdivided and therefore mix intimately with further quantities of gases of combustion entering the intermediate nozzle 22, the mixture being first crowded together and thereafter allowed to expand before entering the extension 1, in which it meets with further quantities of gases entering through the gap between the nozzle 22 and the extension. The whole of the gases and steam will now once more be crowded together before being allowed to expand and the kinetic velocity of the mixture will thereby be once more increased.

A similar effect is obtained in the modification illustrated in Fig. 6. Here the bottom part 23 of the exhaust nozzle is formed with a central branch 24 and a number of lateral branch tubes 25, these latter leading to an annular nozzle 26 of a well known kind so that the steam entering the first of the acceleration nozzles 21, 28, has the form of an annular jet issuing from nozzle 26 and a central jet issuing from nozzle 24. Gases of combustion are drawn into the central part of the nozzle 26 by the jet issuing from the central nozzle 24 and, having transferred to the steam, part of their excess heat rise together with the steam in contact with the inner surface of the annular steam jet issuing from the nozzle 26.

The heated mixture now entering the lower acceleration nozzle 2lcarries along greater quantities of gases of combustion entering through the gap between the nozzles and this mixture is now crowded together and thereafter allowed to expand in the nozzle 21 and, after having carried along more gases, in the nozzle 28, before entering the extension I of the chimney, where another expansion will take place with a corresponding increase of kinetic energy.

Instead of subdividing the blast pipe as shown and described in order to effect a particularly efficient exchange of heat by diffusion, I may also bring about such heat exchange by confining the steam and gases within a guide way of great length, thus crowding them together into intimate contact and at the same time increasing their kinetic velocity by acceleration in a nozzle of a de Laval type.

This is shown in Fig. 7, where 29 is an ordinary blast pipe of supernormal cross-sectional area of passage and 30 a long acceleration nozzle of de Laval section the bottom portion of which embraces the blast pipe nozzle, while its main portion extends high up into the chimney. The mixture of steam and gases entering the acceleration nozzle 29, after having first been crowded together, is allowed to expand while being held in intimate contact throughout the height of the nozzle, until it escapes into the chimney to be once more allowed to expand therein.

The above shows that the transfer of heat from the hot gases of combustion onto the steam and the consequent increase of potential energy of the steam can be brought about in various manners. Similarly the increase of kinetic energy by first throttling the mixture of gases and steam and thereafter allowing them to expand in acceleration nozzles can be effected by means of devices of a varied character.

In Fig. 8 is shown a chinmey 3| as hitherto used with an insert 32 of triangular cross-section mounted in the top part of the chimney to effect a throttling action on the hot mixture of steam and gases. cross-section is shown in Fig. 9. v

In defining the de Laval divergent nozzle, the Encyclopaedia Britannica, 13th edition, vol. 25, pages 842-843, states that in this nozzle the throat or smallest section is approached by a more or less rounded entrance, allowing the stream lines to converge, and from the throat outwards the nozzle expands in any gradual manner, generally in fact as a simple cone. As shown by the illustrations in this encyclopaedia and by the various figures in the present application, a short inflow portion is provided and a comparatively long, outwardly flaring outflow portion usually having a straight taper of increasing cross sectional area.

I wish it to be understood that I do not desire to be limited to the exact details of construction An annular insert 33 of similarv shown and described for obvious modifications will occur to a personskilled in the art.

I claim:-

1. Gas exhausting means for the smoke boxes of locomotive and other boilers comprising a blast pipe subdivided into a plurality of branch nozzles of different length, a chimney mounted above said blast pipe and an acceleration nozzle of the de Laval type between and separated by gaps from said pipe and said chimney.

2. Gas exhausting means for the smoke boxes of locomotive and other boilers comprising a blast pipe, a chimney mounted above said blast pipe and an acceleration nozzle of the de Laval type arranged above said blast pipe and extending high up into said chimney.

3. Gas exhausting means for the smoke boxes of locomotive and other boilers comprising a blast pipe, a chimney, having the form of an acceleration nozzle of the de Laval type and a tapering top portion, mounted above said blast pipe and an acceleration nozzle of the de Laval type between and separated by gaps from said pipe and said chimney.

4. Gas exhausting means for the smoke boxes of locomotive and other boilers comprising a blast pipe, a chimney mounted above said blast pipe, a guide plate above the level of said blast pipe rising from below and surrounding the bottom part of said chimney and an acceleration nozzle of the de Laval type between and separated by gaps from said pipe and said chimney.

5. Gas exhausting means for the smoke boxes of locomotive and other boilers comprising a blast pipe, a chimney mounted above said blast pipe, an inset of wedge-shaped cross-section mounted in the top portion of said chimney to gradually narrow down its free sectional area of passage and an acceleration nozzle of the de Laval type between and separated by gaps from said pipe and said chimney.

6. Gas exhausting means for the smoke boxes of locomotive and other boilers comprising a blast pipe, a chimney mounted above said blast pipe, and an acceleration nozzle mounted between but separated by gaps from said blast pipe and said chimney, thereby receiving the blast from said blast pipe and delivering it at increased velocity into said chimney; the said acceleration nozzle having a short rounded inflow portion and a comparatively long, gradually expanding outflow portionof increasing cross sectional area.

7. The structure of claim 6 wherein a plurality of acceleration nozzles are arranged in series between said blast pipe and said chimney, the blast passing through each of said nozzles in series and then into said chimney.

8. The structure of claim 6 wherein said chimney has the form of an acceleration nozzle of the de Laval type.

9. The structure of claim 6 wherein the chimney has the form of an acceleration nozzle of the de Laval type and has a constricted top portion.

10. The structure of claim 6 wherein the acceleration nozzle ends in branch nozzles of different length.

11. In a locomotive draft appliance, a stack, an exhaust nozzle and at least one intermediate nozzle mounted between but separated by gaps from said exhaust nozzle and said stack, thereby receiving the exhaust from said nozzle and delivering it into said stack; the said intermediate nozzle having a short rounded inflow portion and a comparatively long, gradually expanding outflow portion of increasing cross sectional area.

, KARL BASCHANT. 

